Imaging Method May Enhance Nuclear-Material Detection

Security at U.S. ports could strengthen with a new proof-of-concept technique invented by a consortium of scientists.

Researchers from the Georgia Institute of Technology, University of Pennsylvania, and University of Michigan created a proof-of-concept new imaging method for detecting weapons-grade uranium and plutonium hiding in cargo containers.

Anna Erickson, an assistant professor at Georgia Tech’s School of Mechanical Engineering, said in a statement: “Once heavy shielding is paced around weapons-grade uranium or plutonium, detecting them passively using radiation detectors surrounding a 40-foot-cargo container is very difficult.”

This new technique has an ion accelerator at its core. It uses this component to emit heavy hydrogen isotypes called deuterons, which then hones in on a boron target resulting in a bevy of neutrons and high-energy photons.

Next, the photons can be used to create an image of the materials as they scan the container. Both photons and neutrons stimulate the nuclear substance enabling detection of gamma rays and neutrons.

“When the neutrons interact with fissile materials, they initiate a fission reaction, generating both prompt and delayed neutrons that can be detected despite the shielding. The neutrons do not prompt a time-delayed reaction with non-fissionable materials such as lead, providing an indicator that materials of potential use for development of nuclear weapons are inside the shielding,” according to Georgia Tech’s announcement.

Previous iterations of this detection process relied on X-rays to explore suspicious cargo, but it struggled to bypass heavy shielding and there was a risk that the radiation would harm the innards of container.

By contrast, Erickson’s creation reduces the energy amount that could potentially enter the cargo because of photons and electrons’ discrete energy.